JP4681239B2 - Device and hydraulic block for damping pressure pulsations - Google Patents

Description

  The present invention is a device for damping pressure pulsations, particularly for an electronically controllable vehicle brake device, comprising a casing surrounding the damping chamber, a hydraulic connection opening into the damping chamber, a throttling device, It relates to a type having

  This type of device is particularly useful for reducing inconvenient driving noise in a vehicle brake device. The cause of such driving noise is that a general piston pump is used in a vehicle brake device, and the piston of this piston pump is forcibly reciprocated by an eccentric element that is driven to rotate. According to this reciprocating motion, a pressure medium is periodically supplied, and this pressure medium supply causes pressure pulsation in the connected hydraulic circuit. This pressure pulsation can be heard in the interior of a car and impair comfort.

  A device for damping such pressure pulsations is known, for example, from German Patent Application No. 4234013. FIG. 3 of this known specification shows a hydraulic block (hydroblock) of an electronically controllable vehicle brake device with a receiving hole that forms the casing of the device. The receiving hole is closed by a cover fixed in shape connection (constraint by shape) with respect to the periphery, and defines an attenuation chamber inside. An inflow passage and an outflow passage extending from the pressure generating member are opened in the attenuation chamber. A throttle is disposed at the outlet of the outflow passage.

  This known noise attenuating device has a structure in which the cover and the diaphragm are separate components, and these separate components need to be fixed in a number of successive work stages in the hydraulic block. This is a drawback. The secure fixing of these individual components must be inspected as they are assembled and the pressure medium sealability to the outside must be ensured. This work phase makes the manufacture of the device cumbersome and expensive.

  Accordingly, an object of the present invention is to eliminate the disadvantages of the known noise attenuating device as described above.

This object is achieved according to the invention in that the casing and the throttle device form an attenuation unit which can be assembled in advance externally and which can be fixed in the receiving part, the casing of the attenuation unit being open at least on one side. A hollow body, and a member that substantially closes the opening of the hollow body, wherein the member that substantially closes the opening of the hollow body is in a deep pan shape, and a first end that opens, It has been solved by having a throttle device in the form of at least one throttle hole formed at the closed end of the member .

  The device of the present invention can be pre-assembled externally with respect to the prior art, i.e. the assembly, sealing test and functional test of this device can be performed independently of the assembly of the hydraulic block. , Has the advantage of. The structural unit can then be fastened to the hydraulic block in a few known working steps, is itself relatively compact and requires only a small amount of free space for the fixing tool to act on the hydraulic block. And not.

  Other advantages or advantageous embodiments of the invention are described in the dependent claims or in the description below.

Claims 2 and 3 seek protection for a separate construction of the casing. This casing can be manufactured particularly simply and inexpensively in terms of manufacturing technology due to the features described in claims 2 and 3 . The features of claim 4 avoid an increase in pressure that can be tolerated in relation to the mechanical strength of the structural unit inside the damping device according to the invention. This type of pressure increase may occur due to otherwise clogging of the throttle hole and / or the viscosity of the pressure medium increases with temperature, and over time, in the vehicle brake system. Or the drive unit comprising the electric motor and the eccentric body that loads the pump element is damaged. Claims 5 and 6 relate to a filter structure which is particularly advantageous in terms of cost, and the features of claim 7 limit the structural volume of the damping device and thus provide a particularly compact construction type.

  Embodiments of the invention are illustrated in the drawings and are described in detail below.

  FIG. 1 is a longitudinal sectional view of a first embodiment of a device according to the invention inserted into a receiving part of a hydraulic block of an electronically controlled vehicle brake device, and FIGS. 2 to 7 are variations of the invention. A part is likewise shown in a longitudinal section, and FIG. 8 shows a plan view of the part shown in FIG. The reference numerals used in the following description for corresponding components are used uniformly in all drawings.

FIG. 1 shows a part of a hydraulic block 10 of an electronically controlled vehicle brake device. The hydraulic block 10 has a receiving part 12, and the receiving part 12 has a receiving part 12. A damping unit 14 pre-assembled according to the invention is inserted. For this purpose, the receiving part 12 is formed in a blind hole shape, and its diameter is provided with one step from the outside to the inside. An inflow passage 16 extending in the transverse direction with respect to the longitudinal (longitudinal) axis of the receiving portion 12 is opened in the wall portion region having a large diameter. An outflow passage 18 extending coaxially with respect to the longitudinal axis of the opening opens outward. The inflow path 16 is connected to a hydraulic pressure generator (not shown), and the outflow path 18 is connected in particular to a master brake cylinder (also not shown) of an electronically controlled vehicle brake device. This connection is realized by a pressure medium passage formed in the hydraulic block 10. Even so, it is not always necessary for the function of the damping unit 14 to allow the pressure medium to flow through, i.e. to have a separate inflow path and a separate outflow path. Rather, it is conceivable to provide only one hydraulic connection.

  The damping unit 14 shown in FIG. 1 has a casing 20 assembled from two components. These two components are a sleeve-like hollow body 22 and a deep-bowl-shaped member 24, and since the first end of the hollow body 22 is inserted into the deep-bowl-shaped member 24, The opening of the end face side of the pan-like member 24 is substantially closed. Both the deep-plate-shaped member 24 and the hollow body 22 are made of metal and are firmly connected to each other by a shape connection (constraint by shape) from the outside, preferably by a laser welding connection 26. The pan-like member 24 has a radial opening in the wall section between the bottom surface and the end of the section into which the hollow body 22 is inserted, and this opening flows into the casing 20. A portion 28 is formed. The inflow portion 28 opens into an annular chamber 30 that is obtained by the stepping configuration of the receiving portion 12 and is limited by the wall portion of the receiving portion 12 and the deep pot-like member 24. ing. Similarly, an inflow passage 16 connected to a hydraulic pressure generator is opened in the annular chamber 30.

  On the one hand, the annular chamber 30 is closed in the axial direction by a fixing device 32 which is formed integrally with the end of the deep pot-shaped member 24. The fixing device 32 has a radially protruding cutting edge 34 arranged at the outer end, the outer diameter of the cutting edge 34 being larger than the diameter of the receiving part 12. The fixing device 32 further comprises two ring webs 36 spaced axially from one another in the direction of the bottom surface of the pan-like member 24 and adapted to the diameter of the receiving part 12, and these The ring web 36 and the cutting edge 34 are formed with a groove 38 that is open on the circumferential surface side. In order to fix the damping unit 14 to the hydraulic block 10, the pan-like member 24 is pushed into the receptacle 12, at which time the cutting edge 34 causes the material of the wall of the receptacle 12 to enter the groove 38. Pushing away, thereby providing a shape-coupled and liquid-tight connection between the damping unit 14 and the hydraulic block 10 at the same time. This type of coupling is called so-called self-clinch coupling. Instead of this type of connection, other airtight connections are also conceivable, for example screw connections, weld connections, press connections or tight connections.

  A second seal cross section 40 is integrally formed on the deep pot-like member 24 located on the opposite side of the fixing device 32. The outer diameter of the second seal cross section 40 is matched to the smaller diameter portion of the receiving portion 12, thereby preventing a hydraulic short circuit between the inflow path 16 and the outflow path 18. Furthermore, the deep pot-shaped member 24 has a throttling device 42 in the shape of a throttling hole 43 arranged eccentrically in the bottom region thereof, and the ratio of the length of the throttling hole 43 to the diameter is at least 2. .0. The longitudinal axis of the throttle hole 43 extends parallel to the outflow path 18, and the throttle hole 43 opens in the outflow path 18. Of course, a large number of throttle holes 43 of this type may be selectively provided in the deep pot-shaped member 24. These throttle holes 43 are opened in the outflow passage 18 in common.

  The second end of the hollow body 22, which is not shown in FIG. 1, opposite to the pan-like member 24, is likewise closed, and the necessary closure for this is optionally hollow. It may be configured separately or integrally with the body 22. The casing 20 of the attenuation unit 14 thereby defines an attenuation chamber 44 therein. A filter 48 is inserted into the built-in chamber 46 between the end of the hollow body 22 and the bottom surface of the deep pot-shaped member 24. The hollow body 22 is drawn (tapered) at its end located inside the deep pot-shaped member 24, and the retracted part 50 forms a stopper that guarantees the axial position of the filter 48. ing.

  The filter 48 consists of a filter support 52 made from plastic in an advantageous manner by injection molding techniques, which is formed in a ring and is separated from one another by a web. An opening 54 is provided. These radial openings 54 are covered by a filter fabric 49, which is shown schematically for the sake of clarity, which filter fabric 52 has its edge region when manufacturing the filter support 52 in an advantageous manner. Is embedded by injection molding with plastic material. At both ends of the filter support, sticking seals 56 are integrally formed around the periphery of the filter support. Furthermore, the filter 48 has at least one axial projection 58 at the end directed at least to the bottom surface of the deep pot-like member 24. The protrusion 58 holds the filter 48 with a distance from the bottom surface. The dimensions of the protrusion 58 are selected so that the two seals 56 of the filter support 52 are located on both sides of the inflow portion 28 formed on the wall of the deep pot-shaped member 24. Thereby, the filter medium 49 is operatively connected to the recess 50 of the hollow body 22 so that the dirt is removed by the filter fabric 49 before the pressure medium flowing into the damping unit 14 flows out through the throttle hole 43. . This acts so that the throttle hole 43 is not clogged.

  FIG. 2 shows a second embodiment of the attenuating unit 14. This second embodiment is different from that of the first embodiment shown in FIG. Is different. The deep pot-shaped member 24 includes a sleeve body 60 and a diaphragm plate 62 that are open on both sides. The hollow body 22 is partially inserted into the first end of the sleeve body 60, while the diaphragm plate 62 is fixed to the second end opposite to the hollow body 22 and is arranged eccentrically. For example, one throttle hole 43 is provided. The sleeve body 60 has an inner diameter that is stepped twice. The hollow body 22 is fixed in the smaller diameter section located on the inner side, and the throttle plate 62 is fixed in the larger diameter section. Yes. The hollow body 22 protrudes in the axial direction with respect to the first section having the smaller diameter, and the protruding stepped portion is mechanically expanded. This widened portion 64 is formed by introducing a correspondingly shaped punch into the sleeve body 60 which is still open at this point after the hollow body 22 is assembled and before the diaphragm plate 62 is assembled. . Thereby, an effective shape coupling between the two components and thus a high strength against pressure of the damping unit 14 is obtained. After the filter 48 is inserted into the area of the average inner diameter of the hollow body 60, the diaphragm plate 62 is assembled by pushing and the damping unit 14 is closed. The end face of the filter 48 comes into contact with the end of the hollow body 22 and the inside of the aperture plate 62. The hollow body 22 includes a closed first end formed into a hemispherical ceiling by an inexpensive deep drawing. Thereby, a separate closure can be saved and, in particular, the pressure medium is sealed and a pressure-resistant hollow body 22 is obtained.

  In another embodiment shown in FIG. 3, an elastomeric core 70 is inserted into the damping chamber 44 of the damping unit 14, and the elastomeric core 70 is a fluid volume 72 that exists between the elastomeric core 70 and the filter 48. Except for, the attenuation chamber 44 is completely filled. The fluid volume 72 is in the expanded portion 72 of the hollow body 22. The elastomer core 70 is preferably made of silicone rubber, which is chemically resistant to brake fluid and mechanically resistant to the resulting pressure and vibration loads. ing. Silicone rubber also has a relatively stable volume compressibility over the operating time generated within the important temperature and frequency ranges. The resulting spring properties were met only with an incompressible pressure medium so that the damping unit 14 with the elastomeric core 70 had the necessary elasticity to damp pressure pulsations in the hydraulic system. It makes it possible to have a smaller volume than a comparable damping unit. In other words, the insertion of the elastomer core 70 saves the structural volume of the damping unit 14 and at the same time a potential hazard due to the hollow chambers in the system that tend to collect air bubbles and are difficult to clean. Sex is reduced.

  Structurally, the elastomer core 70 has a through-opening 74 extending concentrically with respect to the longitudinal axis and a longitudinal groove (shown in FIG. 3) formed in the outer peripheral surface of the elastomer core 70 extending in parallel to the through-opening 74. Is not solid) except for. The significance and purpose of the flutes and through-openings 74 are to allow the air enclosed inside the hollow body 22 to be exhausted for better assembly of the elastomer core 70, and to balance the pressure in the elastomer core 70 under operating conditions. To adjust, that is, to avoid partial mechanical overload. For the other structure of the attenuation unit shown in FIG. 3, refer to the description regarding FIG.

  FIG. 4 shows an embodiment of the present invention having an aperture device 42 of another configuration. This embodiment is characterized in that a pressure limiting valve 80 is connected in parallel to the throttle hole 43 in a hydraulic manner. This avoids an increase in pressure beyond that which holds the structural elements together and allows the mechanical load limits of the structural elements. The pressure increase occurs, for example, when the throttle hole 43 is clogged, for example due to dirt, and / or at a low temperature, based on an increase in the viscosity of the pressure medium, and particularly to other structural groups of vehicle brake devices. It adversely affects the functionality of the pressure generator. The diaphragm device 42 according to the modified embodiment described below basically does not need the filter 48 connected in front. However, in certain applications, the throttle device 42 according to this variant embodiment is advantageously provided with a filter 48.

  In the embodiment shown in FIG. 4, the throttle device 42 includes a valve body 82, and the valve body 82 is integrally formed with the dome-shaped valve 84 that enters the inside of the damping unit 14 and the dome-shaped valve 84. And an annular valve flange 86. The valve body 82 is held in the sleeve body 60 by the valve flange 86, and the sleeve body 60 is closed to the outside. A ring-shaped support is in contact with the inside of the valve flange 86, and this support surrounds the dome-shaped valve 84, and its end surface supports the elastomer core 70. The support body is provided with a vertical slit penetrating the peripheral surface.

  In order to form the pressure limiting valve 80, the dome shaped valve 84 has a notch 85 penetrating eccentrically displaced with respect to the longitudinal axis, the notch 85 having its inner end stepped once. ing. At this step 88, a conical valve seat 90 restricts the through-flow cross section 91, which is closed by a valve member 92 in the form of a sphere. For this purpose, a spring element 94 arranged concentrically on the longitudinal axis of the notch 86 acts on the valve member 92. The spring element 94 is supported by a plug 96 that is pushed into the notch. Since the stopper 96 has a gap 98, the pressure medium flowing through the notch 85 can be discharged when the valve seat 90 is opened. The design of the spring element 94 can define a pressure threshold at which the pressure limiting valve 80 opens against the spring force of the spring element 94.

  As described above, the pressure limiting valve 80 is connected in parallel to the throttle hole 43. In the illustrated embodiment, the throttle hole 43 is disposed on the circumferential surface of the dome-shaped valve 84, for example, and is formed by the notch 85. Open in a radial direction in a closed room. Inflow into the throttle hole 43 is performed by the inflow portion 28 formed in the sleeve body 60 and the annular gap 100 formed between the outer peripheral surface of the dome-shaped valve 84 and the inner peripheral surface of the support body 48. In this case, the annular gap 100 is limited in the axial direction by the diameter extension 102 of the dome-shaped valve 84 in the region of the valve flange 86. Of course, in this embodiment, in order to adapt the diaphragm device 42 to each usage example, a large number of such diaphragms 43 may be provided. In this case, the throttle hole 43 is not necessarily arranged in the region of the dome-shaped valve 84, and may be disposed, for example, in the region of the valve flange 86 or on the end face of the dome-shaped valve 84 having the valve seat 90. .

  Another embodiment of the throttle device 42a is shown in FIG. The valve body 82a of this embodiment is advantageously configured as a funnel-shaped deep-drawn portion, and accordingly, a first end with a reduced outer diameter, which forms a through-flow cross section 91a, and an outer diameter of And an enlarged second end. The valve body 82a is held by the stepped hole 106a of the sleeve body 60a in the circumferential direction in the region of the second end portion, and is inclined toward the inside of the stepped hole 106 on the end surface side, for example. It contacts the conical shoulder 108. The spring element 94a having the through notch 112a is fixed on the bottom surface thereof by the bent portion 104 at the second end portion of the valve body 82a. The spring element 94a is configured as a slitted leaf spring, which in its central region has a spherically curved receiving part for the spherically shaped valve member 92a. . The spring element 94a is preloaded, thereby elastically pressing the valve member 92a against the cross-flow cross section 91a. When the pressure in the chamber in front of the through-flow cross section 91a rises, a pressure against the spring element 94a acts toward the valve member 92a. Thereby, the spring element 94a effectively opens the flow-through cross section 91a from a predetermined pressure level, so that the pressure drops. In this embodiment, the throttle hole 43a is configured as a through-flow hole in the section of the valve body 82a that is narrowed in a neck shape.

  The embodiment shown in FIG. 6 shows a throttle device 42b in the stepped hole 106b of the sleeve body 60b. This throttle device 42b has a flat portion on the end side instead of the sphere shown in FIG. And a conical element extending conically toward both ends. The conical element has a longitudinal (longitudinal) hole 110 penetrating in the axial direction, and the first hole section of the longitudinal hole 110 on the side facing the through-flow cross section 91b forms a throttle hole 43b. In addition, the throttle hole 43b is shifted to the second hole section having an enlarged diameter through the step portion. In this embodiment, the valve member 92b is further flowed by the pressure medium. The conical element is connected to the spring element 94b in the region of increased outer diameter of the valve member 92b. Similarly, the spring element 94b configured as a leaf spring has an outer peripheral portion fixed to the valve body 82b, and has through-cutouts 112b distributed over the bottom surface. When the through-flow cross section 91b is opened, The pressure medium flows out through the through cutout 112. In the state shown, the valve member 92b is loaded by the preload of the spring element 94b and closes this cross-flow cross section 91b. The sleeve body 60 and the valve body 82b are configured in the same manner as the embodiment shown in FIG. 5 except for the throttle hole 43b formed in the valve member 92b.

  In the alternative embodiment shown in FIG. 7, no separate valve member is provided. The valve body 82c is manufactured from a material having spring elasticity, for example, spring steel, as a deep drawing portion, and is configured in a bowl shape. The valve body 82c further has an annular wall portion 114, and the valve body 82c is held in contact with the shoulder 108c in the stepped hole 106c of the sleeve body 60c by the wall portion 114. The bottom surface 116 of the valve body 82c shown in FIG. 8 covers the entire cross section of the stepped hole 106, and the through opening disposed at the center of the bottom surface 116 forms the throttle hole 43c. A slit 118 extends in a star shape in the radial direction from the through opening, and a region of the bottom surface existing between the slits 118 forms an elastically deformable spring tongue 120. Due to the pressure load of the spring tongue 120, the bottom surface 116 of the valve body 82c shown in FIG. 7 is bent downward, whereby the through opening 43c is expanded and the pressure level is lowered. 5 to 7, the flow direction of the pressure medium is indicated by a directional arrow R.

  The individual features described in connection with the different embodiments are not restricted to that embodiment, but of course, individual or multiple features can be combined with one another and the variations formed thereby. Does not depart from the idea of the present invention. The idea of the present invention is that the throttle device 42 and the casing 20 can be combined in one attenuation unit 14 that can be pre-assembled externally, for example, whose sealability can be inspected. It is fixed in the receiving part 12 of the hydraulic block 10 of the vehicle brake device which can be electronically controlled by a work stage which can be carried out easily and inexpensively.

1 is a longitudinal sectional view of a first embodiment of a device according to the invention inserted into a receiving part of a hydraulic block of an electronically controlled vehicle brake device. It is a longitudinal cross-sectional view of a part of another embodiment. It is a longitudinal cross-sectional view of a part of another embodiment. It is a longitudinal cross-sectional view of a part of another embodiment. It is a longitudinal cross-sectional view of a part of another embodiment. It is a longitudinal cross-sectional view of a part of another embodiment. It is a longitudinal cross-sectional view of a part of another embodiment. It is a top view of the Example shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Hydraulic block, 12 Receiving part, 14 Damping unit, 16 Inflow path, 18 Outflow path, 20 Casing, 22 Hollow body, 24 Deep-bowl-shaped member, 26 Laser welding connection part, 28 Inflow part, 30 Annular chamber, 32 Fixing device, 34 cutting edge, 36 ring web, 38 groove, 40 seal cross section, 42, 42a throttle device, 43, 43a, 43b throttle hole, 44 damping chamber, 46 installation space, 48 filter, 49 filter fabric, 50 Recess, 52 Filter support, 54 Radial opening, 56 Seal, 58 Protrusion, 60, 60a, 60b Sleeve body, 62 Throttle plate, 64 Widening portion, 66 First end, 70 Elastomer core, 72 Fluid Volume, 74 Through-opening, 80 Pressure limiting valve , 82, 82a, 82b Valve body, 84 Dome-shaped valve, 85 Notch, 86 Valve flange, 88 Step, 90 Valve seat, 91, 91a Cross-flow cross section, 92, 92a, 92b Valve member, 94, 94a Spring element, 96 plugs, 98 gaps, 100 annular gaps, 102 diameter expansion parts, 104 folding parts, 106b stepped holes, 108 shoulders, 110 vertical holes, 112a, 112b through notches, 114 wall parts, 116 bottom faces, 120 spring tongues

Claims (11)

An apparatus for damping pressure pulsations for electronic controllable vehicle brake system, a casing (20) surrounding the damping chamber (44), a hydraulic connection which opens into the damping chamber (44) In the type having the parts (16, 18) and the diaphragm device (42),
The casing (20) and the throttle device (42) form a damping unit (14) that can be preassembled externally and fixed in the receiving part (12), the casing of the damping unit (14) ( 20) has a hollow body (22) that is open on at least one side and a member (24) that substantially closes the opening of the hollow body (22), and the opening of the hollow body (22) The substantially closed member (24) has a pan-like shape and has an open first end and a substantially closed second end, and at least one throttle hole (43). A device for damping pressure pulsations, characterized in that a throttling device (42) in the form of is formed at the closed end of the member (24) . The member (24), which substantially closes the opening of the hollow body (22), has an outer periphery for fixing the damping unit (14) in the receiving part (12) of the hydraulic block (10) of the vehicle brake device. The device according to claim 1, comprising a single-piece fixing device.   A member (24) that substantially closes the opening of the hollow body (22) comprises a sleeve body (60) that is open on both sides, and the hollow body (22) is disposed within the first end of the sleeve body (60). A throttle device (42) in the form of a throttle body (62) having at least one throttle hole (43) and having a first end portion is provided, the throttle body (62) The device according to claim 2, wherein the sleeve is inserted at the end of the sleeve body facing the hollow body. A pressure limiting valve (80) is hydraulically connected in parallel to at least one throttle hole (43) of the throttle device (42), and the pressure limiting valve (80) is formed in front of the throttle hole (43). and the has an openable flow cross-section in accordance with the pressure (91a, 91b), according to claim 1 or 3 apparatus according. A valve member (92, 92a, 92b) is provided to control the through-flow cross section (91, 91a, 91b) of the pressure limiting valve (80), and the valve member is loaded by a spring element (94). The apparatus of claim 4 . Filter on the upstream side of the throttle device (42) (48) is provided, apparatus of any one of claims 1 to 5. The filter (48) is configured as an annular filter through which the pressure medium flows radially, the filter (48) comprising a filter support (52) having a radial opening (54) and a radial opening (54). ) and has at least one filter fabric (49) covering, according to claim 6. The filter support (52) of the filter (48) is manufactured from plastic by injection molding technique, and the filter fabric (49) is injected by the material of the filter support (52) in the edge region of the radial opening. 8. The device of claim 7 , wherein the device is molded and embedded. The damping chamber (44), the elastomeric core made of silicone rubber (70) is inserted, device according to any one of claims 1 to 8. The apparatus of claim 9 , wherein the elastomeric core (70) has at least one through-opening (74) extending axially. A hydraulic block for the electronically controlled vehicle brake system, characterized in that it comprises at least one damping unit of any one of claims 1 to 10 (14), the electronic control Hydraulic block for vehicle-type vehicle brake system.

Images